ATL: DORIAN - Post-Tropical - Discussion

[boca]

It looks to be an ULL still but I'm watching it as well

[GCANE]

Surface pressure has been slowly dropping for the last 48 hrs in the Bahamas

http://www.ndbc.noaa.gov/plot_met.php?s ... _label=EDT

[GCANE]

IMHO, it appears to be picking up the effects of the SW CONUS ridge building thru the GOM.

The ridge is definitely strengthening - loop thru 200mb vorticity.

http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

Can also see it picking up more and more of the UL streamlines on the shear map.

http://tropic.ssec.wisc.edu/real-time/a ... wg8shr.GIF

I hope this is not one of those cork-in-a-champagne-bottle scenarios.

[tolakram]

Live visible: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

[GCANE]

Good number of overshooting tops building cirrus.

http://tropicalatlantic.com/satellite/c ... 23&lon=-77

Can see the effects of the ULL over western Cuba, but not too bad in the convection.

[tolakram]

From the 6z GFS run, you can follow the vorticity ... gets close to Miami and then weakens and moves out to sea.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation

0Z euro shows a similar track but a little better defined. http://moe.met.fsu.edu/cgi-bin/ecmwf-op ... =Animation

[gatorcane]

Live visible: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

Nice vis shot. I see the low-level vorticity still WNW of the blob just west of Grand Bahama. Not sure if this has time to make a comeback or not.

[CalmBeforeStorm]

Good number of overshooting tops building cirrus.

http://tropicalatlantic.com/satellite/c ... 23&lon=-77

Can see the effects of the ULL over western Cuba, but not too bad in the convection.

That ULL is moving quickly to the SW and weakening

[GCANE]

Good number of overshooting tops building cirrus.

http://tropicalatlantic.com/satellite/c ... 23&lon=-77

Can see the effects of the ULL over western Cuba, but not too bad in the convection.

That ULL is moving quickly to the SW and weakening

One good hot tower is all it needs to really crank.

Been firing moderate rain rate all morning.

http://www.nrlmry.navy.mil/htdocs_dyn_p ... bean.0.jpg

[wxman57]

That's still not Dorian's remnants. It's an upper-level low. Dorian's wave axis dissipated days ago.

[artist]

That's still not Dorian's remnants. It's an upper-level low. Dorian's wave axis dissipated days ago.

I'm just curious, why do you think the Miami office thinks it is the remnants? What do you see so we can recognize it?
Miami NWS

DISCUSSION...THE FORECAST THINKING HAS CHANGED LITTLE FROM PREVIOUS
SHIFTS. THE PARTIAL REMNANTS OF DORIAN LIE OVER THE CENTRAL AND SE
BAHAMAS. DRIER AIR CONTINUES ACROSS SOUTH FL AND THE NW BAHAMAS
AHEAD OF THIS FEATURE. SO AGAIN, WILL GO WITH JUST SLIGHT CHANCE
POPS EAST COAST TODAY AND CHANCE INTERIOR-GULF COAST WHERE SCATTERED
SHOWERS AND TSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON WITH THE
SEA BREEZE CONVERGENCE ON THE EASTERLY STEERING WIND FLOW.

and then Melbourne seems to concur with you -
Melbourne NWS -

(PREV DISC) THERE HAS BEEN SOME SUBSIDENCE/DRYING ALOFT ACROSS THE
SOUTH AHEAD OF UPPER LOW MOVING ACROSS THE BAHAMAS. EXPECT THIS
INITIALLY DRIER AIR TO LIMIT POPS ALONG THE SPACE/TREASURE COAST.
MOS POPS ARE ONLY 20 PERCENT THERE AND WILL FOLLOW THOSE VALUES.
HIGHEST POPS LOOK TO BE ACROSS THE NORTH INTERIOR...40-50
PERCENT...WHERE ACTIVITY SHOULD LINGER INTO THE EVENING AGAIN.

or are they talking about 2 different areas of the Bahamas? It gets confusing living near the edge of both offices.

[GCANE]

Overshooting tops still persist even a couple hours after DMAX.

Rain rate now increasing.

[tolakram]

Speeding this loop up I think I can see inflow starting from the SW side of the blob. Certainly looks better than a few days ago.

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=10

[tolakram]

Pressure has fallen over the last few days but rising today.

http://www.ndbc.noaa.gov/show_plot.php? ... _label=EDT

http://www.ndbc.noaa.gov/station_page.php?station=SPGF1

[wxman57]

That's still not Dorian's remnants. It's an upper-level low. Dorian's wave axis dissipated days ago.

I'm just curious, why do you think the Miami office thinks it is the remnants? What do you see so we can recognize it?
Miami NWS...

Perhaps they find it easier to call the upper low the remnants of Dorian than to describe it as an upper low to the general public? I suppose that some of Dorian's moisture was entrained by the upper low as the wave axis passed. So, technically, the Miami office may be correct in calling it Dorian's remnants (the moisture). But the tropical wave that was Dorian dissipated. If another storm developed in the Bahamas then it would not be called Dorian.

[artist]

That's still not Dorian's remnants. It's an upper-level low. Dorian's wave axis dissipated days ago.

I'm just curious, why do you think the Miami office thinks it is the remnants? What do you see so we can recognize it?
Miami NWS...

Perhaps they find it easier to call the upper low the remnants of Dorian than to describe it as an upper low to the general public? I suppose that some of Dorian's moisture was entrained by the upper low as the wave axis passed. So, technically, the Miami office may be correct in calling it Dorian's remnants (the moisture). But the tropical wave that was Dorian dissipated. If another storm developed in the Bahamas then it would not be called Dorian.

thank you for your answer. That seriously helps to explain alot.

[jhpigott]

Anybody thinks this gets re-tagged as an invest?

[northjaxpro]

Anybody thinks this gets re-tagged as an invest?

Surface pressures have to start to show a pattern of falling over a period of time IMO and convection has to sustain itself also for a period of time. Should these two instances occur later on , then maybe NHC designates this as another invest.

[hurricanekid416]

Is it dorian? What do the conditions look like for it?

[ronjon]

Convection keeps increasing with a little more model support from the 12z globals and I'd say yes it gets tagged again as a INVEST.